21012133231 has 8 divisors (see below), whose sum is σ = 22129172720. Its totient is φ = 19896207552.

The previous prime is 21012133217. The next prime is 21012133273. The reversal of 21012133231 is 13233121012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012133231 - 2²¹ = 21010036079 is a prime.

It is a super-2 number, since 2×21012133231² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012133199 and 21012133208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012133031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239580 + ... + 315313.

It is an arithmetic number, because the mean of its divisors is an integer number (2766146590).

Almost surely, 2^21012133231 is an apocalyptic number.

21012133231 is a deficient number, since it is larger than the sum of its proper divisors (1117039489).

21012133231 is a wasteful number, since it uses less digits than its factorization.

21012133231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556905.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21012133231 its reverse (13233121012), we get a palindrome (34245254243).

The spelling of 21012133231 in words is "twenty-one billion, twelve million, one hundred thirty-three thousand, two hundred thirty-one".